# Boolean Rules A+AB=A

#### Yami

Joined Jan 18, 2016
337
Can you use the rule as follows A+AB'=A?

#### crutschow

Joined Mar 14, 2008
26,066
Yes, you can.

#### WBahn

Joined Mar 31, 2012
26,398
You can even use A+AB=A if you're careful.

#### Yami

Joined Jan 18, 2016
337
You can even use A+AB=A if you're careful.
Hehehe what do you mean?

#### Yami

Joined Jan 18, 2016
337
so does B'+AB= B ? it shouldn't right?

if B'=1
1+A(0)=1

if B'=0
0+A(1)=A

#### bertus

Joined Apr 5, 2008
21,057
Hello,

It only works in the case : A + AB

You are right, in your shown case B and B' are not the same so it does not work.

Bertus

#### Yami

Joined Jan 18, 2016
337
Hello,

It only works in the case : A + AB

You are right, in your shown case B and B' are not the same so it does not work.

Bertus
but A+AB'=A works (does B') have any effect

#### bertus

Joined Apr 5, 2008
21,057
Hello,

Yes, as (1 + B) give a 1 as result, but (1 + B') also gives a 1 as result.
A 1 orred with any value will give a 1 as result.

Bertus